Advanced Cryo-Electron Microscopy Technology Group

Overview

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A cryo-electron microscopy image

The Advanced Cryo-Electron Microscopy Technology Group explores emerging imaging platforms and develops methodologies, focusing on projects with the potential to make cryo-EM a more widely accessible technique. 

The team focuses on single-particle analysis and cryo-electron tomography. Our group aims to push resolution limits on our 200 kV CryoARM microscope to compare its performance to the more popular 300 kV microscopes. Our structure-determination methods are initially developed on standard cryo-EM specimens, such as beta-galactosidase, and later applied to more biologically relevant samples, especially where high-resolution information is needed to provide mechanistic insights.  Ultimately, the goal is to sufficiently streamline the process to efficiently obtain high-resolution cryo-EM structures for a broad range of targets. 

We work with the National Cryo-Electron Microscopy Facility to improve its services and support provided to the research community. 

Innovations

We engaged with an application engineer from JEOL to develop optimized data collection procedures for the CryoARM microscope. These procedures were used to obtain a 1.8Å structure of beta glactosidase, which was published in the journal IUCrJ in 2020.  Further improvements to the process have recently produced a 1.6Å structure of the same sample. 

Focus

Development and application of cryo-EM methods 

Video file
1.6 Å cryo-EM structure of b-galactosidase obtained using CryoARM200 equipped with a K3 camera
  • Push resolution and size limits of the cryo-EM technique, and optimize the workflows so they are suitable for challenging, medically important specimens. 
  • Apply single-particle cryo-EM to explore the structural determinants of the regulation of gene expression, including: 
    • transcription factor specificity 
    • cis-acting regulatory elements 
    • effects of chemical modifications 
  • Combine information from cryo-electron tomography and single-particle analysis to gain insights into molecular mechanisms of signaling, including: 
    • protein-protein interactions 
    • transmembrane signal transduction 
    • cell-cell communication 
  • Use high-resolution structures and emerging computational methods for analyzing conformational heterogeneity to study the chemistry and dynamics of enzyme catalysis, including: 
    • roles of metals in enzyme activity 
    • conformational landscapes of enzymes 
    • allosteric regulation 

Technology

Lower voltage cryo-EM microscopes 

  • CryoARM200 
  • Glacios